None of Indonesia’s 22 tsunami warning buoys, installed in 2004 after over 150,000 people were killed by a massive tsunami triggered by a 9.1 magnitude earthquake, were working when a 7.8 temblor struck the region late Wednesday. Although initial fears of another regionwide disaster faded after tsunami warnings were lifted, the earthquake, which struck about 500 miles from Padang in West Sumatra province, has raised doubts over the country’s readiness to deal with similar incidents in the future.

Sutopo Purwo Nugroho, a spokesman for the country’s National Disaster Management Agency, reportedly said Thursday that all of the 22 buoys in the area needed to be replaced, adding that authorities need 11 trillion rupiah ($831 million) for a “tsunami master plan program” that would include building evacuation shelters and improving the buoy system.

Another official cited by the Wall Street Journal blamed the malfunctions on vandalism by fishermen.

The buoys, operated by Indonesia, were installed by the country with the help of foreign donors in 2006 to capture and transmit any changes on the ocean bed after an earthquake to predict an oncoming tsunami. The buoys are part of a multimillion-dollar warning system that includes seabed detection devices and sirens.

After Wednesday night’s quake, which was felt across much of Sumatra, a tsunami alert was initially issued. However, sirens went off in some coastal towns but not in others.

“This is not a trivial matter,” Costas Synolakis, director the Tsunami Research Center at the University of Southern California, told the Journal. “False warnings diminish the credibility of the system, people become cynical and complacent.”

Five other buoys in the region, operated by India, Thailand, the U.S. and Australia, were working, according to media reports. However, those are much further from the Sumatran coastline than the Indonesia-operated buoys.